1. Field of Invention
The field of invention relates to recumbent tricycles. Our invention applies to recumbent tricycles which are either manually propelled by the vehicle operator or by the application of external power either as a primary driving force or as a secondary source of power assistance on demand. The value of our invention is in enhancing the performance of the tricycle While the nature of the tricycle and its operating characteristics, as derived from our invention, maximize the innovation to the performance and operating characteristics; our invention is equally useable on quadracycle apparatus which can similarly be either operator propelled or propelled in whole or in part by external power.
2. Description of the Prior Art
Various recumbent tricycle apparatus of various configurations have been utilized in the prior art. The most common tricycle configuration uses two wheels in contact with the ground to push a forward single or plural wheel, also in contact with the ground, to steer the apparatus in the general direction established by pointing the leading steering wheels. Where the prior art deviates from a single or plural forward steerable wheel, none apply only a single differential to the leading drive wheels as the primary steering for the apparatus. In the prior art that attempts to use the individual drive wheels for steering, clutch and differential-clutch mechanisms or drive belt slippage are the principle operators for steering.
Tricycles have been used for many years. They have generally consisted of two wheels to the rear with a single steering wheel to the front. This configuration while satisfactory for small children is inherently unstable if speed or fast turning is involved. U.S. Pat. No. 4,826,190 to Hartman dated May, 1989 is an attempt to increase stability by extending and lowering the tricycle frame, however this design sacrifices turning radius and would requires a large area to maneuver. U.S. Pat. No. 4,925,202 to Baker May, 15, 1990 reversed the arrangement of the wheel and used only one of the two front wheels to drive with, the other front wheel is used to brake with, and the rear wheel is the steering mechanism. While this configuration is more maneuverable, the one sided braking and driving of the front wheels limit the stability. Foreign Patent with U.S. Pat. No. 5,071,150 by Conrad Dec. 10, 1991 is an attempt to increase maneuverability but at the expense of added unnecessary weight in the form of a counter weight used to help lift the front wheel off the ground so rear brakes can be used to pivot the tricycle in a short radius. Foreign Patent U.S. Pat. No. 4,484,646 by Smith Nov. 27, 1984 has a low center of gravity and is maneuverable but its drive mechanism would only be effective if used in conjunction with a motor.
Our invention's novelty resides in the organization of the drive wheels in relationship to the forward direction of the apparatus' motion, combines plural drive wheels with the steering and braking functions, utilizes a recumbent operator position, applies a low center of gravity with the center of inertia positioned sufficiently low to maximize the shortness of the apparatus' turning radius without sacrificing stability or requiring a reduction in speed. The novel combination of these parameters results in an unusually comfortable, stable, and extremely maneuverable riding characteristic in our invention, which is achieved because the direct mechanical link between the power and driving mechanisms is continuous. In addition to the novel combination and organization referred to above, a simple friction based dampening device is added to the trailing caster wheel to compensate for varying degrees of operator skill and for changes in driving condition or driving environment for which a infinitely variable steering sensitivity would be of advantage to the operator and which can be employed and adjusted by the operator while operating the apparatus.
As such, it may be appreciated that there be a need for a new and improved tricycle apparatus as set forth in the instant invention wherein the innovative organization of tricycle components and the unique application of mechanisms provided by the instant invention addresses the ease and comfort of use, fun of operation, enhanced maneuverability and operating stability in a novel invention with a broad application to satisfy a diverse range of users, from youth to senior. Our invention substantially fulfills these needs and deviates from prior art by not disengaging the mechanical link between the source of input power and the driving wheels as in a clutch, nor by reliance on an imprecise and difficult to maintain inefficiency, as in the case of slipping drive belts on each drive wheel, and by allowing for control of steering responsiveness in an inherently stabile apparatus.